I just rewatched TUC and got a giggle from that scene. I explained it away as perhaps he was sleeping in a smaller set of quarters/ready room near the bridge for quick access. I remembered touring the USS Lexington and that the captain had a small room off the bridge in addition to his larger quarters.

I just took it that Meyers depicted Starfleet as a more militaristic organisation, and military ships tend to be cramped.